Inghouse electric



C. LE G. FORTESCUE. TERMINAL FOR ELECTROLYTIC CONDENSERS.

APPLICATION FILED IAN. I6, 1919.

Patented June 28, 1921.

R O T N E V W WITNESSES:

ATTORNEY an electrolyticbath. I, I I

I knownthat the terminals of apparatus of the character aboveidesig UNITED STATES PATENT OFFICE,

0mm LE G.- FORTESCU'EQOFIPITTSBURGH,-PEN'NSYLVANIA, ASSIGNOR T0 was!- j. me'nousn' mac-r310 a" MANUFACTURING" comm-NY n conrom'rrow or 1 mm- SYLYANIAI.

To all whom it'ma'y concern l Be it known that I, CHARLES LE G; For- TESICU'E, a subject of the King of Great Britainfandja resident of Pittsburgh, in the county'l'of Allegheny and State of Pennsyl vania, have invented'a new and useful Imrovement in Terminals for Electrolytic ondensers, of which the following 1s a:

Q specification;

My invention relates to terminals for electrodes of electrolytic condensers, lightning arresters, rectifiersandthe' like through which thefelectric current enters and leaves Itis commonly nated 'become'corroded, during use, at their points of emergence from the electrolyte" into the air" or other gases abovethe electro- 1yte.- The rate of" corrosion varies some what with" different electrolytes, their chemical, composition and their concentra-- tion. l In 'time, the corrosion mayreach such depth as to so weaken the electrode terminal as to cause it'to 'fbreak from its own weight or from jars or vibrations to which it may be sub ected.o Some electrolytes,

which are electrically satisfactory, are not applicable to commercial use on account of rapid detoriati oniof the terminals employed in connection therewith. Other electrolytes, which are. satisfactory at the outset, in a short time become so concentrated by evaporation that they attack and corrode the,

terminals. I l I v I Furthermore, this corro'slon or incrustation of the terminals,particularly in electrolytic condensers, causes a serious current leakagejand, consequently, a material watt terminals at; -the juncture of the electrol te and the supernatant gas, and an salt ormationj upon thefterminals at these points,

nal s, thereby maintaining substantially zero potential'between thesleeves and the terminalsp H, I I

The p imar object of my nvention resides, therefore, inf the provision of a S1II1-' ple andefl'ective means for preventing'cor- Specification of Letters Patent.

. which the" terminals 4 are connectedrfAt the; .pointswhere the terminals4 emerge; from Tamar. m nmoraofirrcldonnmsaas} ro'sion of'the electrode terminals. retai'ri- I I PatentedJune 28, 1921". Application flled'J'anuary s, 1919. Seria' I' 'No. 271,462. i a

ing a portion of electrolyte, adjacent the surface thereof, between the "terminals and sleeves connected thereto. v Another object of m inven i i i t9 Pm:

'vide an electrode terminal" for condensers, rectifiers, lightning 'arresters "and thelike which shallobviate corrosion atth'e' points where the terminals emerge from'the electrolyteandtherebyincrease the length of continuous serve of such apparatus;

With these and other objects in" v'iew, my

invention will be more fully described, illustrated in the drawings, in which corresponding numerals indicate like parts, and then particularly pointed outin the claims.

In the drawings, F gure 1 is aside view,

partly in elevation and 'partlyin' section, vof

an ordinary electrolyticfcondenser"to which. 'my invention is applied, and Fig, 2 isa perspective vlew, onla larger scale, of 'a tel};

minal constructed in accordance with my] invention. v

In order to insure a clear and accurate understanding ofniy' invention, I have shown, in the drawing, anelec'trolytic Cong denser comprising a tank 1 ;formedlof or other suitable mati rial and anelec'trol tel 2 contained therein. Two" series of" suita 1e? plates 3 of any desirable material such, for

, example, as aluminum, are alternately connected in the usual manner'by-terminals 4 which are preferably"oi similar material, the plates 3 havingprojecting portionsfi to surround them, each being connected to itsterminal by'having its end so restricted as I I, v to closely engagethe same, as indicated at 7 I have discovered that corrosion of, the

6 permit access of electrolyte into the sleeve as well as facilitate the fastening of it to the terminal. Each sleeve may be connected to its respective terminal by constricting either of its ends but it is preferably connected at the end beneath the surface of the electrolyte, the other, or open end extending above the surface of the electrolyte.

Although the sleeves may be of any filmforming material, I have found that good results may be obtained by employing material similar to that utilized as the terminal. A non-film-forming material may be employed but, in such cases, waterproof coatings should be applied to the sleeves to prevent attack by the electrolyte with which they are in contact.

The corrosion of a terminal, embodying my invention, when applied to an electrolytic condenser or similar apparatus, is pre vented by employing a sleeve, preferably of film-forming material, which may be replaced when corrosion has so affected it as to impair its efiiciency. The sleeve, being connected to the terminal by frictional engagement, may be constructed of suflicient length to allow gradual withdrawal of the sleeve from the electrolyte as corrosion occurs and destroys its effectiveness at the point where it emerges from the electrolyte. In this manner, a sleeve may be practically entirely used up.

Corrosion of the terminal of the condenser is prevented on account of the fact that the sleeve is mechanically and electrically connected to the terminal and, therefore, the potential between the terminal and the surrounding sleeve is at all times substantially zero. The electrolyte immediately surrounding the terminal, being screened off from the main body of solution and being positioned between members of zero difference of potential, will not corrode the terminal, since there will be no current flow between the terminal and that portion of the electrolyte immediately surrounding it. However, sparkling and consequent corrosion will occur on the exterior of the sleeve surrounding the terminal at the surface where it emerges from the electrolyte. This corrosion of the terminal-projecting sleeve is exactly similar to that experienced with terminals not protected. Although the sleeve must be renewed at intervals, it may be made relatively inexpensive and may be constructed in such manner as not to require detachment of any parts of the condenser in order to replace it. Furthermore, approximately all of the material of the sleeve may be used up by gradually removing the sleeve from the electrolyte as it de; teriorates.

It is obvious that, with minor changes in the construction and material, other forms of terminals for condensers, rectifiers and the like, may be constructed without departing from the spirit of my invention, and I desire, therefore, that no limitations shall be imposed except such as are indicated in the appended claims.

I claim as my invention:

1. A method of preventing corrosion of the terminal of an electrode of a condenser, rectifier, lightning arrester or the like that comprises interposing a sleeve of conducting material between the main body of electrolyte and the portion adjacent the terminal and connecting the sleeve to the terminal to maintain substantially zero difference of potential between the sleeve and the terminal.

2. A method of preventing corrosion of the terminal of an electrode of a condenser, rectifier, lightning arrester or the like that comprises interposing a split sleeve of conducting material between the main body of electrolyte and the portion adjacent the terminal and connecting the sleeve to the terminal to maintain substantially zero difference of potential between the sleeve and the terminal.

3. A method of preventing corrosion of the terminal of an electrode of a condenser, rectifier, lightning arrester or the like that comprises connecting a split aluminum sleeve to the terminal and interposing it between the main body of electrolyte and the portion adjacent the terminal.

4. In a condenser, rectifier, lightning arrester or the like, the combination with a container, an electrolyte therein and an electrode projecting from the electrolyte, of a conducting sleeve surrounding the terminal and connected to the terminal to establish substantially zero potential between the sleeve and the terminal.

5. In a condenser, rectifier, lightning arrester or the like, the combination with a container, an electrolyte therein and an electrode projecting from the electrolyte, of a split conducting sleeve surrounding the terminal adjacent the surface of the electrolyte and connected to the terminal to establish substantially zero potential between the sleeve and the terminal.

6. In a condenser, rectifier, lightning arrester or the like, the combination with a container, an electrolyte therein and an electrode projecting from the electrolyte, of a split sleeve of film-forming material surrounding the terminal adjacent the surface of the electrolyte and connected to the terminal to establish substantially zero potential between the sleeve and the terminal.

7. A terminal for electrolytic condensers, rectifiers, lightning arresters and the like comprising a conductor and a sleeve of conducting material engaging and surrounding, the conductor.

8. A terminal for electrolytic condensers,'

I rectifiers, lightning arresters and the like comprising a conductor and a split sleeve of num sleeve having 15 conducting material engaging the conductor at one of 1ts ends and surrounding the same.

10. A terminal for electrolytic condensers, rectifiers, lightnin arresters and the like comprising a con uctor and a split alumia constricted end engaging the conductor. 7

11. A terminal for electrolytic condensers,

rectifieis, lightning arresters and the like comprising a conductor and a split sleeve of film-forming material connected to the conductor and surrounding the same.

12; A method of reventing corrosion ofthe terminal of an e ectrode of a condenser,

rectifier, lightning arrester or the like that comprises interposing a sleeve of film-forming material between themain body of electrolyte and the portion adjacent the terminal and connecting said sleeve to said terminal to maintain substantially zero potential between the sleeve and the terminal.

In testimony whereof I havehereunto subscribed m name this 27th day of Dec, 1918. C ARLES LEG. FORTESCUE. 

